diff mbox series

[v2,13/15] drm/amdgpu: Use mmu_range_insert instead of hmm_mirror

Message ID 20191028201032.6352-14-jgg@ziepe.ca (mailing list archive)
State Superseded
Delegated to: Jason Gunthorpe
Headers show
Series Consolidate the mmu notifier interval_tree and locking | expand

Commit Message

Jason Gunthorpe Oct. 28, 2019, 8:10 p.m. UTC
From: Jason Gunthorpe <jgg@mellanox.com>

Remove the interval tree in the driver and rely on the tree maintained by
the mmu_notifier for delivering mmu_notifier invalidation callbacks.

For some reason amdgpu has a very complicated arrangement where it tries
to prevent duplicate entries in the interval_tree, this is not necessary,
each amdgpu_bo can be its own stand alone entry. interval_tree already
allows duplicates and overlaps in the tree.

Also, there is no need to remove entries upon a release callback, the
mmu_range API safely allows objects to remain registered beyond the
lifetime of the mm. The driver only has to stop touching the pages during
release.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: David (ChunMing) Zhou <David1.Zhou@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h           |   2 +
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  |   5 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    |   1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c        | 341 ++++--------------
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h        |   4 -
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.h    |  13 +-
 6 files changed, 84 insertions(+), 282 deletions(-)

Comments

Christian König Oct. 29, 2019, 7:51 a.m. UTC | #1
Am 28.10.19 um 21:10 schrieb Jason Gunthorpe:
> From: Jason Gunthorpe <jgg@mellanox.com>
>
> Remove the interval tree in the driver and rely on the tree maintained by
> the mmu_notifier for delivering mmu_notifier invalidation callbacks.
>
> For some reason amdgpu has a very complicated arrangement where it tries
> to prevent duplicate entries in the interval_tree, this is not necessary,
> each amdgpu_bo can be its own stand alone entry. interval_tree already
> allows duplicates and overlaps in the tree.
>
> Also, there is no need to remove entries upon a release callback, the
> mmu_range API safely allows objects to remain registered beyond the
> lifetime of the mm. The driver only has to stop touching the pages during
> release.
>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: David (ChunMing) Zhou <David1.Zhou@amd.com>
> Cc: amd-gfx@lists.freedesktop.org
> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h           |   2 +
>   .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  |   5 +-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    |   1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c        | 341 ++++--------------
>   drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h        |   4 -
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.h    |  13 +-
>   6 files changed, 84 insertions(+), 282 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index bd37df5dd6d048..60591a5d420021 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1006,6 +1006,8 @@ struct amdgpu_device {
>   	struct mutex  lock_reset;
>   	struct amdgpu_doorbell_index doorbell_index;
>   
> +	struct mutex			notifier_lock;
> +
>   	int asic_reset_res;
>   	struct work_struct		xgmi_reset_work;
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> index 6d021ecc8d598f..47700302a08b7f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> @@ -481,8 +481,7 @@ static void remove_kgd_mem_from_kfd_bo_list(struct kgd_mem *mem,
>    *
>    * Returns 0 for success, negative errno for errors.
>    */
> -static int init_user_pages(struct kgd_mem *mem, struct mm_struct *mm,
> -			   uint64_t user_addr)
> +static int init_user_pages(struct kgd_mem *mem, uint64_t user_addr)
>   {
>   	struct amdkfd_process_info *process_info = mem->process_info;
>   	struct amdgpu_bo *bo = mem->bo;
> @@ -1195,7 +1194,7 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
>   	add_kgd_mem_to_kfd_bo_list(*mem, avm->process_info, user_addr);
>   
>   	if (user_addr) {
> -		ret = init_user_pages(*mem, current->mm, user_addr);
> +		ret = init_user_pages(*mem, user_addr);
>   		if (ret)
>   			goto allocate_init_user_pages_failed;
>   	}
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 5a1939dbd4e3e6..38f97998aaddb2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -2633,6 +2633,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>   	mutex_init(&adev->virt.vf_errors.lock);
>   	hash_init(adev->mn_hash);
>   	mutex_init(&adev->lock_reset);
> +	mutex_init(&adev->notifier_lock);
>   	mutex_init(&adev->virt.dpm_mutex);
>   	mutex_init(&adev->psp.mutex);
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> index 31d4deb5d29484..4ffd7b90f4d907 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> @@ -50,66 +50,6 @@
>   #include "amdgpu.h"
>   #include "amdgpu_amdkfd.h"
>   
> -/**
> - * struct amdgpu_mn_node
> - *
> - * @it: interval node defining start-last of the affected address range
> - * @bos: list of all BOs in the affected address range
> - *
> - * Manages all BOs which are affected of a certain range of address space.
> - */
> -struct amdgpu_mn_node {
> -	struct interval_tree_node	it;
> -	struct list_head		bos;
> -};
> -
> -/**
> - * amdgpu_mn_destroy - destroy the HMM mirror
> - *
> - * @work: previously sheduled work item
> - *
> - * Lazy destroys the notifier from a work item
> - */
> -static void amdgpu_mn_destroy(struct work_struct *work)
> -{
> -	struct amdgpu_mn *amn = container_of(work, struct amdgpu_mn, work);
> -	struct amdgpu_device *adev = amn->adev;
> -	struct amdgpu_mn_node *node, *next_node;
> -	struct amdgpu_bo *bo, *next_bo;
> -
> -	mutex_lock(&adev->mn_lock);
> -	down_write(&amn->lock);
> -	hash_del(&amn->node);
> -	rbtree_postorder_for_each_entry_safe(node, next_node,
> -					     &amn->objects.rb_root, it.rb) {
> -		list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
> -			bo->mn = NULL;
> -			list_del_init(&bo->mn_list);
> -		}
> -		kfree(node);
> -	}
> -	up_write(&amn->lock);
> -	mutex_unlock(&adev->mn_lock);
> -
> -	hmm_mirror_unregister(&amn->mirror);
> -	kfree(amn);
> -}
> -
> -/**
> - * amdgpu_hmm_mirror_release - callback to notify about mm destruction
> - *
> - * @mirror: the HMM mirror (mm) this callback is about
> - *
> - * Shedule a work item to lazy destroy HMM mirror.
> - */
> -static void amdgpu_hmm_mirror_release(struct hmm_mirror *mirror)
> -{
> -	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
> -
> -	INIT_WORK(&amn->work, amdgpu_mn_destroy);
> -	schedule_work(&amn->work);
> -}
> -
>   /**
>    * amdgpu_mn_lock - take the write side lock for this notifier
>    *
> @@ -133,157 +73,86 @@ void amdgpu_mn_unlock(struct amdgpu_mn *mn)
>   }
>   
>   /**
> - * amdgpu_mn_read_lock - take the read side lock for this notifier
> - *
> - * @amn: our notifier
> - */
> -static int amdgpu_mn_read_lock(struct amdgpu_mn *amn, bool blockable)
> -{
> -	if (blockable)
> -		down_read(&amn->lock);
> -	else if (!down_read_trylock(&amn->lock))
> -		return -EAGAIN;
> -
> -	return 0;
> -}
> -
> -/**
> - * amdgpu_mn_read_unlock - drop the read side lock for this notifier
> - *
> - * @amn: our notifier
> - */
> -static void amdgpu_mn_read_unlock(struct amdgpu_mn *amn)
> -{
> -	up_read(&amn->lock);
> -}
> -
> -/**
> - * amdgpu_mn_invalidate_node - unmap all BOs of a node
> + * amdgpu_mn_invalidate_gfx - callback to notify about mm change
>    *
> - * @node: the node with the BOs to unmap
> - * @start: start of address range affected
> - * @end: end of address range affected
> + * @mrn: the range (mm) is about to update
> + * @range: details on the invalidation
>    *
>    * Block for operations on BOs to finish and mark pages as accessed and
>    * potentially dirty.
>    */
> -static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
> -				      unsigned long start,
> -				      unsigned long end)
> +static bool amdgpu_mn_invalidate_gfx(struct mmu_range_notifier *mrn,
> +				     const struct mmu_notifier_range *range)
>   {
> -	struct amdgpu_bo *bo;
> +	struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
> +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
>   	long r;
>   
> -	list_for_each_entry(bo, &node->bos, mn_list) {
> -
> -		if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start, end))
> -			continue;
> -
> -		r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv,
> -			true, false, MAX_SCHEDULE_TIMEOUT);
> -		if (r <= 0)
> -			DRM_ERROR("(%ld) failed to wait for user bo\n", r);
> -	}
> +	/* FIXME: Is this necessary? */

Most likely not.

Christian.

> +	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
> +					  range->end))
> +		return true;
> +
> +	if (!mmu_notifier_range_blockable(range))
> +		return false;
> +
> +	mutex_lock(&adev->notifier_lock);
> +	r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
> +				      MAX_SCHEDULE_TIMEOUT);
> +	mutex_unlock(&adev->notifier_lock);
> +	if (r <= 0)
> +		DRM_ERROR("(%ld) failed to wait for user bo\n", r);
> +	return true;
>   }
>   
> +static const struct mmu_range_notifier_ops amdgpu_mn_gfx_ops = {
> +	.invalidate = amdgpu_mn_invalidate_gfx,
> +};
> +
>   /**
> - * amdgpu_mn_sync_pagetables_gfx - callback to notify about mm change
> + * amdgpu_mn_invalidate_hsa - callback to notify about mm change
>    *
> - * @mirror: the hmm_mirror (mm) is about to update
> - * @update: the update start, end address
> + * @mrn: the range (mm) is about to update
> + * @range: details on the invalidation
>    *
> - * Block for operations on BOs to finish and mark pages as accessed and
> - * potentially dirty.
> + * We temporarily evict the BO attached to this range. This necessitates
> + * evicting all user-mode queues of the process.
>    */
> -static int
> -amdgpu_mn_sync_pagetables_gfx(struct hmm_mirror *mirror,
> -			      const struct mmu_notifier_range *update)
> +static bool amdgpu_mn_invalidate_hsa(struct mmu_range_notifier *mrn,
> +				     const struct mmu_notifier_range *range)
>   {
> -	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
> -	unsigned long start = update->start;
> -	unsigned long end = update->end;
> -	bool blockable = mmu_notifier_range_blockable(update);
> -	struct interval_tree_node *it;
> -
> -	/* notification is exclusive, but interval is inclusive */
> -	end -= 1;
> -
> -	/* TODO we should be able to split locking for interval tree and
> -	 * amdgpu_mn_invalidate_node
> -	 */
> -	if (amdgpu_mn_read_lock(amn, blockable))
> -		return -EAGAIN;
> -
> -	it = interval_tree_iter_first(&amn->objects, start, end);
> -	while (it) {
> -		struct amdgpu_mn_node *node;
> -
> -		if (!blockable) {
> -			amdgpu_mn_read_unlock(amn);
> -			return -EAGAIN;
> -		}
> +	struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
> +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
>   
> -		node = container_of(it, struct amdgpu_mn_node, it);
> -		it = interval_tree_iter_next(it, start, end);
> +	/* FIXME: Is this necessary? */
> +	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
> +					  range->end))
> +		return true;
>   
> -		amdgpu_mn_invalidate_node(node, start, end);
> -	}
> +	if (!mmu_notifier_range_blockable(range))
> +		return false;
>   
> -	amdgpu_mn_read_unlock(amn);
> +	mutex_lock(&adev->notifier_lock);
> +	amdgpu_amdkfd_evict_userptr(bo->kfd_bo, bo->notifier.mm);
> +	mutex_unlock(&adev->notifier_lock);
>   
> -	return 0;
> +	return true;
>   }
>   
> -/**
> - * amdgpu_mn_sync_pagetables_hsa - callback to notify about mm change
> - *
> - * @mirror: the hmm_mirror (mm) is about to update
> - * @update: the update start, end address
> - *
> - * We temporarily evict all BOs between start and end. This
> - * necessitates evicting all user-mode queues of the process. The BOs
> - * are restorted in amdgpu_mn_invalidate_range_end_hsa.
> - */
> -static int
> -amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror *mirror,
> -			      const struct mmu_notifier_range *update)
> +static const struct mmu_range_notifier_ops amdgpu_mn_hsa_ops = {
> +	.invalidate = amdgpu_mn_invalidate_hsa,
> +};
> +
> +static int amdgpu_mn_sync_pagetables(struct hmm_mirror *mirror,
> +				     const struct mmu_notifier_range *update)
>   {
>   	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
> -	unsigned long start = update->start;
> -	unsigned long end = update->end;
> -	bool blockable = mmu_notifier_range_blockable(update);
> -	struct interval_tree_node *it;
>   
> -	/* notification is exclusive, but interval is inclusive */
> -	end -= 1;
> -
> -	if (amdgpu_mn_read_lock(amn, blockable))
> -		return -EAGAIN;
> -
> -	it = interval_tree_iter_first(&amn->objects, start, end);
> -	while (it) {
> -		struct amdgpu_mn_node *node;
> -		struct amdgpu_bo *bo;
> -
> -		if (!blockable) {
> -			amdgpu_mn_read_unlock(amn);
> -			return -EAGAIN;
> -		}
> -
> -		node = container_of(it, struct amdgpu_mn_node, it);
> -		it = interval_tree_iter_next(it, start, end);
> -
> -		list_for_each_entry(bo, &node->bos, mn_list) {
> -			struct kgd_mem *mem = bo->kfd_bo;
> -
> -			if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
> -							 start, end))
> -				amdgpu_amdkfd_evict_userptr(mem, amn->mm);
> -		}
> -	}
> -
> -	amdgpu_mn_read_unlock(amn);
> +	if (!mmu_notifier_range_blockable(update))
> +		return false;
>   
> +	down_read(&amn->lock);
> +	up_read(&amn->lock);
>   	return 0;
>   }
>   
> @@ -295,12 +164,10 @@ amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror *mirror,
>   
>   static struct hmm_mirror_ops amdgpu_hmm_mirror_ops[] = {
>   	[AMDGPU_MN_TYPE_GFX] = {
> -		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_gfx,
> -		.release = amdgpu_hmm_mirror_release
> +		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables,
>   	},
>   	[AMDGPU_MN_TYPE_HSA] = {
> -		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_hsa,
> -		.release = amdgpu_hmm_mirror_release
> +		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables,
>   	},
>   };
>   
> @@ -327,7 +194,8 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>   	}
>   
>   	hash_for_each_possible(adev->mn_hash, amn, node, key)
> -		if (AMDGPU_MN_KEY(amn->mm, amn->type) == key)
> +		if (AMDGPU_MN_KEY(amn->mirror.hmm->mmu_notifier.mm,
> +				  amn->type) == key)
>   			goto release_locks;
>   
>   	amn = kzalloc(sizeof(*amn), GFP_KERNEL);
> @@ -337,10 +205,8 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>   	}
>   
>   	amn->adev = adev;
> -	amn->mm = mm;
>   	init_rwsem(&amn->lock);
>   	amn->type = type;
> -	amn->objects = RB_ROOT_CACHED;
>   
>   	amn->mirror.ops = &amdgpu_hmm_mirror_ops[type];
>   	r = hmm_mirror_register(&amn->mirror, mm);
> @@ -369,100 +235,33 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>    * @bo: amdgpu buffer object
>    * @addr: userptr addr we should monitor
>    *
> - * Registers an HMM mirror for the given BO at the specified address.
> + * Registers a mmu_notifier for the given BO at the specified address.
>    * Returns 0 on success, -ERRNO if anything goes wrong.
>    */
>   int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
>   {
> -	unsigned long end = addr + amdgpu_bo_size(bo) - 1;
> -	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> -	enum amdgpu_mn_type type =
> -		bo->kfd_bo ? AMDGPU_MN_TYPE_HSA : AMDGPU_MN_TYPE_GFX;
> -	struct amdgpu_mn *amn;
> -	struct amdgpu_mn_node *node = NULL, *new_node;
> -	struct list_head bos;
> -	struct interval_tree_node *it;
> -
> -	amn = amdgpu_mn_get(adev, type);
> -	if (IS_ERR(amn))
> -		return PTR_ERR(amn);
> -
> -	new_node = kmalloc(sizeof(*new_node), GFP_KERNEL);
> -	if (!new_node)
> -		return -ENOMEM;
> -
> -	INIT_LIST_HEAD(&bos);
> -
> -	down_write(&amn->lock);
> -
> -	while ((it = interval_tree_iter_first(&amn->objects, addr, end))) {
> -		kfree(node);
> -		node = container_of(it, struct amdgpu_mn_node, it);
> -		interval_tree_remove(&node->it, &amn->objects);
> -		addr = min(it->start, addr);
> -		end = max(it->last, end);
> -		list_splice(&node->bos, &bos);
> -	}
> -
> -	if (!node)
> -		node = new_node;
> +	if (bo->kfd_bo)
> +		bo->notifier.ops = &amdgpu_mn_hsa_ops;
>   	else
> -		kfree(new_node);
> -
> -	bo->mn = amn;
> -
> -	node->it.start = addr;
> -	node->it.last = end;
> -	INIT_LIST_HEAD(&node->bos);
> -	list_splice(&bos, &node->bos);
> -	list_add(&bo->mn_list, &node->bos);
> +		bo->notifier.ops = &amdgpu_mn_gfx_ops;
>   
> -	interval_tree_insert(&node->it, &amn->objects);
> -
> -	up_write(&amn->lock);
> -
> -	return 0;
> +	return mmu_range_notifier_insert(&bo->notifier, addr,
> +					 amdgpu_bo_size(bo), current->mm);
>   }
>   
>   /**
> - * amdgpu_mn_unregister - unregister a BO for HMM mirror updates
> + * amdgpu_mn_unregister - unregister a BO for notifier updates
>    *
>    * @bo: amdgpu buffer object
>    *
> - * Remove any registration of HMM mirror updates from the buffer object.
> + * Remove any registration of mmu notifier updates from the buffer object.
>    */
>   void amdgpu_mn_unregister(struct amdgpu_bo *bo)
>   {
> -	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> -	struct amdgpu_mn *amn;
> -	struct list_head *head;
> -
> -	mutex_lock(&adev->mn_lock);
> -
> -	amn = bo->mn;
> -	if (amn == NULL) {
> -		mutex_unlock(&adev->mn_lock);
> +	if (!bo->notifier.mm)
>   		return;
> -	}
> -
> -	down_write(&amn->lock);
> -
> -	/* save the next list entry for later */
> -	head = bo->mn_list.next;
> -
> -	bo->mn = NULL;
> -	list_del_init(&bo->mn_list);
> -
> -	if (list_empty(head)) {
> -		struct amdgpu_mn_node *node;
> -
> -		node = container_of(head, struct amdgpu_mn_node, bos);
> -		interval_tree_remove(&node->it, &amn->objects);
> -		kfree(node);
> -	}
> -
> -	up_write(&amn->lock);
> -	mutex_unlock(&adev->mn_lock);
> +	mmu_range_notifier_remove(&bo->notifier);
> +	bo->notifier.mm = NULL;
>   }
>   
>   /* flags used by HMM internal, not related to CPU/GPU PTE flags */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
> index b8ed68943625c2..d73ab2947b22b2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
> @@ -39,12 +39,10 @@ enum amdgpu_mn_type {
>    * struct amdgpu_mn
>    *
>    * @adev: amdgpu device pointer
> - * @mm: process address space
>    * @type: type of MMU notifier
>    * @work: destruction work item
>    * @node: hash table node to find structure by adev and mn
>    * @lock: rw semaphore protecting the notifier nodes
> - * @objects: interval tree containing amdgpu_mn_nodes
>    * @mirror: HMM mirror function support
>    *
>    * Data for each amdgpu device and process address space.
> @@ -52,7 +50,6 @@ enum amdgpu_mn_type {
>   struct amdgpu_mn {
>   	/* constant after initialisation */
>   	struct amdgpu_device	*adev;
> -	struct mm_struct	*mm;
>   	enum amdgpu_mn_type	type;
>   
>   	/* only used on destruction */
> @@ -63,7 +60,6 @@ struct amdgpu_mn {
>   
>   	/* objects protected by lock */
>   	struct rw_semaphore	lock;
> -	struct rb_root_cached	objects;
>   
>   #ifdef CONFIG_HMM_MIRROR
>   	/* HMM mirror */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> index 658f4c9779b704..4b44ab850f94c2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> @@ -30,6 +30,9 @@
>   
>   #include <drm/amdgpu_drm.h>
>   #include "amdgpu.h"
> +#ifdef CONFIG_MMU_NOTIFIER
> +#include <linux/mmu_notifier.h>
> +#endif
>   
>   #define AMDGPU_BO_INVALID_OFFSET	LONG_MAX
>   #define AMDGPU_BO_MAX_PLACEMENTS	3
> @@ -100,10 +103,12 @@ struct amdgpu_bo {
>   	struct ttm_bo_kmap_obj		dma_buf_vmap;
>   	struct amdgpu_mn		*mn;
>   
> -	union {
> -		struct list_head	mn_list;
> -		struct list_head	shadow_list;
> -	};
> +
> +#ifdef CONFIG_MMU_NOTIFIER
> +	struct mmu_range_notifier	notifier;
> +#endif
> +
> +	struct list_head		shadow_list;
>   
>   	struct kgd_mem                  *kfd_bo;
>   };
Jason Gunthorpe Oct. 29, 2019, 1:59 p.m. UTC | #2
On Tue, Oct 29, 2019 at 07:51:30AM +0000, Koenig, Christian wrote:
> > +static bool amdgpu_mn_invalidate_gfx(struct mmu_range_notifier *mrn,
> > +				     const struct mmu_notifier_range *range)
> >   {
> > -	struct amdgpu_bo *bo;
> > +	struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
> > +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> >   	long r;
> >   
> > -	list_for_each_entry(bo, &node->bos, mn_list) {
> > -
> > -		if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start, end))
> > -			continue;
> > -
> > -		r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv,
> > -			true, false, MAX_SCHEDULE_TIMEOUT);
> > -		if (r <= 0)
> > -			DRM_ERROR("(%ld) failed to wait for user bo\n", r);
> > -	}
> > +	/* FIXME: Is this necessary? */
> 
> Most likely not.
> 
> Christian.
> 
> > +	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
> > +					  range->end))
> > +		return true;

So is the bo->tbo.mem.num_pages == bo->tbo.ttm.num_pages always?

And userptr can't be zero here, or at least it doesn't matter if it is?

> > +static bool amdgpu_mn_invalidate_hsa(struct mmu_range_notifier *mrn,
> > +				     const struct mmu_notifier_range *range)
> >   {
> > -	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
> > -	unsigned long start = update->start;
> > -	unsigned long end = update->end;
> > -	bool blockable = mmu_notifier_range_blockable(update);
> > -	struct interval_tree_node *it;
> > -
> > -	/* notification is exclusive, but interval is inclusive */
> > -	end -= 1;
> > -
> > -	/* TODO we should be able to split locking for interval tree and
> > -	 * amdgpu_mn_invalidate_node
> > -	 */
> > -	if (amdgpu_mn_read_lock(amn, blockable))
> > -		return -EAGAIN;
> > -
> > -	it = interval_tree_iter_first(&amn->objects, start, end);
> > -	while (it) {
> > -		struct amdgpu_mn_node *node;
> > -
> > -		if (!blockable) {
> > -			amdgpu_mn_read_unlock(amn);
> > -			return -EAGAIN;
> > -		}
> > +	struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
> > +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> >   
> > -		node = container_of(it, struct amdgpu_mn_node, it);
> > -		it = interval_tree_iter_next(it, start, end);
> > +	/* FIXME: Is this necessary? */
> > +	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
> > +					  range->end))
> > +		return true;
> >   
> > -		amdgpu_mn_invalidate_node(node, start, end);
> > -	}

This one too right?

Jason
Felix Kuehling Oct. 29, 2019, 10:14 p.m. UTC | #3
On 2019-10-28 4:10 p.m., Jason Gunthorpe wrote:
> From: Jason Gunthorpe <jgg@mellanox.com>
>
> Remove the interval tree in the driver and rely on the tree maintained by
> the mmu_notifier for delivering mmu_notifier invalidation callbacks.
>
> For some reason amdgpu has a very complicated arrangement where it tries
> to prevent duplicate entries in the interval_tree, this is not necessary,
> each amdgpu_bo can be its own stand alone entry. interval_tree already
> allows duplicates and overlaps in the tree.
>
> Also, there is no need to remove entries upon a release callback, the
> mmu_range API safely allows objects to remain registered beyond the
> lifetime of the mm. The driver only has to stop touching the pages during
> release.
>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: David (ChunMing) Zhou <David1.Zhou@amd.com>
> Cc: amd-gfx@lists.freedesktop.org
> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h           |   2 +
>   .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  |   5 +-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    |   1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c        | 341 ++++--------------
>   drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h        |   4 -
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.h    |  13 +-
>   6 files changed, 84 insertions(+), 282 deletions(-)
[snip]
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> index 31d4deb5d29484..4ffd7b90f4d907 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
[snip]
> @@ -50,66 +50,6 @@
>   #include "amdgpu.h"
>   #include "amdgpu_amdkfd.h"
>   
> -/**
> - * struct amdgpu_mn_node
> - *
> - * @it: interval node defining start-last of the affected address range
> - * @bos: list of all BOs in the affected address range
> - *
> - * Manages all BOs which are affected of a certain range of address space.
> - */
> -struct amdgpu_mn_node {
> -	struct interval_tree_node	it;
> -	struct list_head		bos;
> -};
> -
> -/**
> - * amdgpu_mn_destroy - destroy the HMM mirror
> - *
> - * @work: previously sheduled work item
> - *
> - * Lazy destroys the notifier from a work item
> - */
> -static void amdgpu_mn_destroy(struct work_struct *work)
> -{
> -	struct amdgpu_mn *amn = container_of(work, struct amdgpu_mn, work);
> -	struct amdgpu_device *adev = amn->adev;
> -	struct amdgpu_mn_node *node, *next_node;
> -	struct amdgpu_bo *bo, *next_bo;
> -
> -	mutex_lock(&adev->mn_lock);
> -	down_write(&amn->lock);
> -	hash_del(&amn->node);
> -	rbtree_postorder_for_each_entry_safe(node, next_node,
> -					     &amn->objects.rb_root, it.rb) {
> -		list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
> -			bo->mn = NULL;
> -			list_del_init(&bo->mn_list);
> -		}
> -		kfree(node);
> -	}
> -	up_write(&amn->lock);
> -	mutex_unlock(&adev->mn_lock);
> -
> -	hmm_mirror_unregister(&amn->mirror);
> -	kfree(amn);
> -}
> -
> -/**
> - * amdgpu_hmm_mirror_release - callback to notify about mm destruction
> - *
> - * @mirror: the HMM mirror (mm) this callback is about
> - *
> - * Shedule a work item to lazy destroy HMM mirror.
> - */
> -static void amdgpu_hmm_mirror_release(struct hmm_mirror *mirror)
> -{
> -	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
> -
> -	INIT_WORK(&amn->work, amdgpu_mn_destroy);
> -	schedule_work(&amn->work);
> -}
> -
>   /**
>    * amdgpu_mn_lock - take the write side lock for this notifier
>    *
> @@ -133,157 +73,86 @@ void amdgpu_mn_unlock(struct amdgpu_mn *mn)
>   }
>   
>   /**
> - * amdgpu_mn_read_lock - take the read side lock for this notifier
> - *
> - * @amn: our notifier
> - */
> -static int amdgpu_mn_read_lock(struct amdgpu_mn *amn, bool blockable)
> -{
> -	if (blockable)
> -		down_read(&amn->lock);
> -	else if (!down_read_trylock(&amn->lock))
> -		return -EAGAIN;
> -
> -	return 0;
> -}
> -
> -/**
> - * amdgpu_mn_read_unlock - drop the read side lock for this notifier
> - *
> - * @amn: our notifier
> - */
> -static void amdgpu_mn_read_unlock(struct amdgpu_mn *amn)
> -{
> -	up_read(&amn->lock);
> -}
> -
> -/**
> - * amdgpu_mn_invalidate_node - unmap all BOs of a node
> + * amdgpu_mn_invalidate_gfx - callback to notify about mm change
>    *
> - * @node: the node with the BOs to unmap
> - * @start: start of address range affected
> - * @end: end of address range affected
> + * @mrn: the range (mm) is about to update
> + * @range: details on the invalidation
>    *
>    * Block for operations on BOs to finish and mark pages as accessed and
>    * potentially dirty.
>    */
> -static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
> -				      unsigned long start,
> -				      unsigned long end)
> +static bool amdgpu_mn_invalidate_gfx(struct mmu_range_notifier *mrn,
> +				     const struct mmu_notifier_range *range)
>   {
> -	struct amdgpu_bo *bo;
> +	struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
> +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
>   	long r;
>   
> -	list_for_each_entry(bo, &node->bos, mn_list) {
> -
> -		if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start, end))
> -			continue;
> -
> -		r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv,
> -			true, false, MAX_SCHEDULE_TIMEOUT);
> -		if (r <= 0)
> -			DRM_ERROR("(%ld) failed to wait for user bo\n", r);
> -	}
> +	/* FIXME: Is this necessary? */
> +	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
> +					  range->end))
> +		return true;
> +
> +	if (!mmu_notifier_range_blockable(range))
> +		return false;
> +
> +	mutex_lock(&adev->notifier_lock);
> +	r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
> +				      MAX_SCHEDULE_TIMEOUT);
> +	mutex_unlock(&adev->notifier_lock);
> +	if (r <= 0)
> +		DRM_ERROR("(%ld) failed to wait for user bo\n", r);
> +	return true;
>   }
>   
> +static const struct mmu_range_notifier_ops amdgpu_mn_gfx_ops = {
> +	.invalidate = amdgpu_mn_invalidate_gfx,
> +};
> +
>   /**
> - * amdgpu_mn_sync_pagetables_gfx - callback to notify about mm change
> + * amdgpu_mn_invalidate_hsa - callback to notify about mm change
>    *
> - * @mirror: the hmm_mirror (mm) is about to update
> - * @update: the update start, end address
> + * @mrn: the range (mm) is about to update
> + * @range: details on the invalidation
>    *
> - * Block for operations on BOs to finish and mark pages as accessed and
> - * potentially dirty.
> + * We temporarily evict the BO attached to this range. This necessitates
> + * evicting all user-mode queues of the process.
>    */
> -static int
> -amdgpu_mn_sync_pagetables_gfx(struct hmm_mirror *mirror,
> -			      const struct mmu_notifier_range *update)
> +static bool amdgpu_mn_invalidate_hsa(struct mmu_range_notifier *mrn,
> +				     const struct mmu_notifier_range *range)
>   {
> -	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
> -	unsigned long start = update->start;
> -	unsigned long end = update->end;
> -	bool blockable = mmu_notifier_range_blockable(update);
> -	struct interval_tree_node *it;
> -
> -	/* notification is exclusive, but interval is inclusive */
> -	end -= 1;
> -
> -	/* TODO we should be able to split locking for interval tree and
> -	 * amdgpu_mn_invalidate_node
> -	 */
> -	if (amdgpu_mn_read_lock(amn, blockable))
> -		return -EAGAIN;
> -
> -	it = interval_tree_iter_first(&amn->objects, start, end);
> -	while (it) {
> -		struct amdgpu_mn_node *node;
> -
> -		if (!blockable) {
> -			amdgpu_mn_read_unlock(amn);
> -			return -EAGAIN;
> -		}
> +	struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
> +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
>   
> -		node = container_of(it, struct amdgpu_mn_node, it);
> -		it = interval_tree_iter_next(it, start, end);
> +	/* FIXME: Is this necessary? */
> +	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
> +					  range->end))
> +		return true;
>   
> -		amdgpu_mn_invalidate_node(node, start, end);
> -	}
> +	if (!mmu_notifier_range_blockable(range))
> +		return false;
>   
> -	amdgpu_mn_read_unlock(amn);
> +	mutex_lock(&adev->notifier_lock);
> +	amdgpu_amdkfd_evict_userptr(bo->kfd_bo, bo->notifier.mm);
> +	mutex_unlock(&adev->notifier_lock);
>   
> -	return 0;
> +	return true;
>   }
>   
> -/**
> - * amdgpu_mn_sync_pagetables_hsa - callback to notify about mm change
> - *
> - * @mirror: the hmm_mirror (mm) is about to update
> - * @update: the update start, end address
> - *
> - * We temporarily evict all BOs between start and end. This
> - * necessitates evicting all user-mode queues of the process. The BOs
> - * are restorted in amdgpu_mn_invalidate_range_end_hsa.
> - */
> -static int
> -amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror *mirror,
> -			      const struct mmu_notifier_range *update)
> +static const struct mmu_range_notifier_ops amdgpu_mn_hsa_ops = {
> +	.invalidate = amdgpu_mn_invalidate_hsa,
> +};
> +
> +static int amdgpu_mn_sync_pagetables(struct hmm_mirror *mirror,
> +				     const struct mmu_notifier_range *update)
>   {
>   	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
> -	unsigned long start = update->start;
> -	unsigned long end = update->end;
> -	bool blockable = mmu_notifier_range_blockable(update);
> -	struct interval_tree_node *it;
>   
> -	/* notification is exclusive, but interval is inclusive */
> -	end -= 1;
> -
> -	if (amdgpu_mn_read_lock(amn, blockable))
> -		return -EAGAIN;
> -
> -	it = interval_tree_iter_first(&amn->objects, start, end);
> -	while (it) {
> -		struct amdgpu_mn_node *node;
> -		struct amdgpu_bo *bo;
> -
> -		if (!blockable) {
> -			amdgpu_mn_read_unlock(amn);
> -			return -EAGAIN;
> -		}
> -
> -		node = container_of(it, struct amdgpu_mn_node, it);
> -		it = interval_tree_iter_next(it, start, end);
> -
> -		list_for_each_entry(bo, &node->bos, mn_list) {
> -			struct kgd_mem *mem = bo->kfd_bo;
> -
> -			if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
> -							 start, end))
> -				amdgpu_amdkfd_evict_userptr(mem, amn->mm);
> -		}
> -	}
> -
> -	amdgpu_mn_read_unlock(amn);
> +	if (!mmu_notifier_range_blockable(update))
> +		return false;

This should return -EAGAIN. Not sure it matters much, because this whole 
function disappears in the next commit in the series. It seems to be 
only vestigial at this point.

Regards,
   Felix

>   
> +	down_read(&amn->lock);
> +	up_read(&amn->lock);
>   	return 0;
>   }
>   
> @@ -295,12 +164,10 @@ amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror *mirror,
>   
>   static struct hmm_mirror_ops amdgpu_hmm_mirror_ops[] = {
>   	[AMDGPU_MN_TYPE_GFX] = {
> -		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_gfx,
> -		.release = amdgpu_hmm_mirror_release
> +		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables,
>   	},
>   	[AMDGPU_MN_TYPE_HSA] = {
> -		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_hsa,
> -		.release = amdgpu_hmm_mirror_release
> +		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables,
>   	},
>   };
>   
> @@ -327,7 +194,8 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>   	}
>   
>   	hash_for_each_possible(adev->mn_hash, amn, node, key)
> -		if (AMDGPU_MN_KEY(amn->mm, amn->type) == key)
> +		if (AMDGPU_MN_KEY(amn->mirror.hmm->mmu_notifier.mm,
> +				  amn->type) == key)
>   			goto release_locks;
>   
>   	amn = kzalloc(sizeof(*amn), GFP_KERNEL);
> @@ -337,10 +205,8 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>   	}
>   
>   	amn->adev = adev;
> -	amn->mm = mm;
>   	init_rwsem(&amn->lock);
>   	amn->type = type;
> -	amn->objects = RB_ROOT_CACHED;
>   
>   	amn->mirror.ops = &amdgpu_hmm_mirror_ops[type];
>   	r = hmm_mirror_register(&amn->mirror, mm);
> @@ -369,100 +235,33 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>    * @bo: amdgpu buffer object
>    * @addr: userptr addr we should monitor
>    *
> - * Registers an HMM mirror for the given BO at the specified address.
> + * Registers a mmu_notifier for the given BO at the specified address.
>    * Returns 0 on success, -ERRNO if anything goes wrong.
>    */
>   int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
>   {
> -	unsigned long end = addr + amdgpu_bo_size(bo) - 1;
> -	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> -	enum amdgpu_mn_type type =
> -		bo->kfd_bo ? AMDGPU_MN_TYPE_HSA : AMDGPU_MN_TYPE_GFX;
> -	struct amdgpu_mn *amn;
> -	struct amdgpu_mn_node *node = NULL, *new_node;
> -	struct list_head bos;
> -	struct interval_tree_node *it;
> -
> -	amn = amdgpu_mn_get(adev, type);
> -	if (IS_ERR(amn))
> -		return PTR_ERR(amn);
> -
> -	new_node = kmalloc(sizeof(*new_node), GFP_KERNEL);
> -	if (!new_node)
> -		return -ENOMEM;
> -
> -	INIT_LIST_HEAD(&bos);
> -
> -	down_write(&amn->lock);
> -
> -	while ((it = interval_tree_iter_first(&amn->objects, addr, end))) {
> -		kfree(node);
> -		node = container_of(it, struct amdgpu_mn_node, it);
> -		interval_tree_remove(&node->it, &amn->objects);
> -		addr = min(it->start, addr);
> -		end = max(it->last, end);
> -		list_splice(&node->bos, &bos);
> -	}
> -
> -	if (!node)
> -		node = new_node;
> +	if (bo->kfd_bo)
> +		bo->notifier.ops = &amdgpu_mn_hsa_ops;
>   	else
> -		kfree(new_node);
> -
> -	bo->mn = amn;
> -
> -	node->it.start = addr;
> -	node->it.last = end;
> -	INIT_LIST_HEAD(&node->bos);
> -	list_splice(&bos, &node->bos);
> -	list_add(&bo->mn_list, &node->bos);
> +		bo->notifier.ops = &amdgpu_mn_gfx_ops;
>   
> -	interval_tree_insert(&node->it, &amn->objects);
> -
> -	up_write(&amn->lock);
> -
> -	return 0;
> +	return mmu_range_notifier_insert(&bo->notifier, addr,
> +					 amdgpu_bo_size(bo), current->mm);
>   }
>   
>   /**
> - * amdgpu_mn_unregister - unregister a BO for HMM mirror updates
> + * amdgpu_mn_unregister - unregister a BO for notifier updates
>    *
>    * @bo: amdgpu buffer object
>    *
> - * Remove any registration of HMM mirror updates from the buffer object.
> + * Remove any registration of mmu notifier updates from the buffer object.
>    */
>   void amdgpu_mn_unregister(struct amdgpu_bo *bo)
>   {
> -	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> -	struct amdgpu_mn *amn;
> -	struct list_head *head;
> -
> -	mutex_lock(&adev->mn_lock);
> -
> -	amn = bo->mn;
> -	if (amn == NULL) {
> -		mutex_unlock(&adev->mn_lock);
> +	if (!bo->notifier.mm)
>   		return;
> -	}
> -
> -	down_write(&amn->lock);
> -
> -	/* save the next list entry for later */
> -	head = bo->mn_list.next;
> -
> -	bo->mn = NULL;
> -	list_del_init(&bo->mn_list);
> -
> -	if (list_empty(head)) {
> -		struct amdgpu_mn_node *node;
> -
> -		node = container_of(head, struct amdgpu_mn_node, bos);
> -		interval_tree_remove(&node->it, &amn->objects);
> -		kfree(node);
> -	}
> -
> -	up_write(&amn->lock);
> -	mutex_unlock(&adev->mn_lock);
> +	mmu_range_notifier_remove(&bo->notifier);
> +	bo->notifier.mm = NULL;
>   }
>   
>   /* flags used by HMM internal, not related to CPU/GPU PTE flags */
[snip]
Jason Gunthorpe Oct. 29, 2019, 11:09 p.m. UTC | #4
On Tue, Oct 29, 2019 at 10:14:29PM +0000, Kuehling, Felix wrote:

> > +static const struct mmu_range_notifier_ops amdgpu_mn_hsa_ops = {
> > +	.invalidate = amdgpu_mn_invalidate_hsa,
> > +};
> > +
> > +static int amdgpu_mn_sync_pagetables(struct hmm_mirror *mirror,
> > +				     const struct mmu_notifier_range *update)
> >   {
> >   	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
> > -	unsigned long start = update->start;
> > -	unsigned long end = update->end;
> > -	bool blockable = mmu_notifier_range_blockable(update);
> > -	struct interval_tree_node *it;
> >   
> > -	/* notification is exclusive, but interval is inclusive */
> > -	end -= 1;
> > -
> > -	if (amdgpu_mn_read_lock(amn, blockable))
> > -		return -EAGAIN;
> > -
> > -	it = interval_tree_iter_first(&amn->objects, start, end);
> > -	while (it) {
> > -		struct amdgpu_mn_node *node;
> > -		struct amdgpu_bo *bo;
> > -
> > -		if (!blockable) {
> > -			amdgpu_mn_read_unlock(amn);
> > -			return -EAGAIN;
> > -		}
> > -
> > -		node = container_of(it, struct amdgpu_mn_node, it);
> > -		it = interval_tree_iter_next(it, start, end);
> > -
> > -		list_for_each_entry(bo, &node->bos, mn_list) {
> > -			struct kgd_mem *mem = bo->kfd_bo;
> > -
> > -			if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
> > -							 start, end))
> > -				amdgpu_amdkfd_evict_userptr(mem, amn->mm);
> > -		}
> > -	}
> > -
> > -	amdgpu_mn_read_unlock(amn);
> > +	if (!mmu_notifier_range_blockable(update))
> > +		return false;
> 
> This should return -EAGAIN. Not sure it matters much, because this whole 
> function disappears in the next commit in the series. It seems to be 
> only vestigial at this point.

Right, the only reason it is still here is that I couldn't really tell
if this:

> > +	down_read(&amn->lock);
> > +	up_read(&amn->lock);
> >   	return 0;
> >   }

Was serving as the 'driver lock' in the hmm scheme... If not then the
whole thing should just be deleted at this point.

I fixed the EAGAIN though

Jason
diff mbox series

Patch

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index bd37df5dd6d048..60591a5d420021 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1006,6 +1006,8 @@  struct amdgpu_device {
 	struct mutex  lock_reset;
 	struct amdgpu_doorbell_index doorbell_index;
 
+	struct mutex			notifier_lock;
+
 	int asic_reset_res;
 	struct work_struct		xgmi_reset_work;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 6d021ecc8d598f..47700302a08b7f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -481,8 +481,7 @@  static void remove_kgd_mem_from_kfd_bo_list(struct kgd_mem *mem,
  *
  * Returns 0 for success, negative errno for errors.
  */
-static int init_user_pages(struct kgd_mem *mem, struct mm_struct *mm,
-			   uint64_t user_addr)
+static int init_user_pages(struct kgd_mem *mem, uint64_t user_addr)
 {
 	struct amdkfd_process_info *process_info = mem->process_info;
 	struct amdgpu_bo *bo = mem->bo;
@@ -1195,7 +1194,7 @@  int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
 	add_kgd_mem_to_kfd_bo_list(*mem, avm->process_info, user_addr);
 
 	if (user_addr) {
-		ret = init_user_pages(*mem, current->mm, user_addr);
+		ret = init_user_pages(*mem, user_addr);
 		if (ret)
 			goto allocate_init_user_pages_failed;
 	}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 5a1939dbd4e3e6..38f97998aaddb2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2633,6 +2633,7 @@  int amdgpu_device_init(struct amdgpu_device *adev,
 	mutex_init(&adev->virt.vf_errors.lock);
 	hash_init(adev->mn_hash);
 	mutex_init(&adev->lock_reset);
+	mutex_init(&adev->notifier_lock);
 	mutex_init(&adev->virt.dpm_mutex);
 	mutex_init(&adev->psp.mutex);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index 31d4deb5d29484..4ffd7b90f4d907 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -50,66 +50,6 @@ 
 #include "amdgpu.h"
 #include "amdgpu_amdkfd.h"
 
-/**
- * struct amdgpu_mn_node
- *
- * @it: interval node defining start-last of the affected address range
- * @bos: list of all BOs in the affected address range
- *
- * Manages all BOs which are affected of a certain range of address space.
- */
-struct amdgpu_mn_node {
-	struct interval_tree_node	it;
-	struct list_head		bos;
-};
-
-/**
- * amdgpu_mn_destroy - destroy the HMM mirror
- *
- * @work: previously sheduled work item
- *
- * Lazy destroys the notifier from a work item
- */
-static void amdgpu_mn_destroy(struct work_struct *work)
-{
-	struct amdgpu_mn *amn = container_of(work, struct amdgpu_mn, work);
-	struct amdgpu_device *adev = amn->adev;
-	struct amdgpu_mn_node *node, *next_node;
-	struct amdgpu_bo *bo, *next_bo;
-
-	mutex_lock(&adev->mn_lock);
-	down_write(&amn->lock);
-	hash_del(&amn->node);
-	rbtree_postorder_for_each_entry_safe(node, next_node,
-					     &amn->objects.rb_root, it.rb) {
-		list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
-			bo->mn = NULL;
-			list_del_init(&bo->mn_list);
-		}
-		kfree(node);
-	}
-	up_write(&amn->lock);
-	mutex_unlock(&adev->mn_lock);
-
-	hmm_mirror_unregister(&amn->mirror);
-	kfree(amn);
-}
-
-/**
- * amdgpu_hmm_mirror_release - callback to notify about mm destruction
- *
- * @mirror: the HMM mirror (mm) this callback is about
- *
- * Shedule a work item to lazy destroy HMM mirror.
- */
-static void amdgpu_hmm_mirror_release(struct hmm_mirror *mirror)
-{
-	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
-
-	INIT_WORK(&amn->work, amdgpu_mn_destroy);
-	schedule_work(&amn->work);
-}
-
 /**
  * amdgpu_mn_lock - take the write side lock for this notifier
  *
@@ -133,157 +73,86 @@  void amdgpu_mn_unlock(struct amdgpu_mn *mn)
 }
 
 /**
- * amdgpu_mn_read_lock - take the read side lock for this notifier
- *
- * @amn: our notifier
- */
-static int amdgpu_mn_read_lock(struct amdgpu_mn *amn, bool blockable)
-{
-	if (blockable)
-		down_read(&amn->lock);
-	else if (!down_read_trylock(&amn->lock))
-		return -EAGAIN;
-
-	return 0;
-}
-
-/**
- * amdgpu_mn_read_unlock - drop the read side lock for this notifier
- *
- * @amn: our notifier
- */
-static void amdgpu_mn_read_unlock(struct amdgpu_mn *amn)
-{
-	up_read(&amn->lock);
-}
-
-/**
- * amdgpu_mn_invalidate_node - unmap all BOs of a node
+ * amdgpu_mn_invalidate_gfx - callback to notify about mm change
  *
- * @node: the node with the BOs to unmap
- * @start: start of address range affected
- * @end: end of address range affected
+ * @mrn: the range (mm) is about to update
+ * @range: details on the invalidation
  *
  * Block for operations on BOs to finish and mark pages as accessed and
  * potentially dirty.
  */
-static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
-				      unsigned long start,
-				      unsigned long end)
+static bool amdgpu_mn_invalidate_gfx(struct mmu_range_notifier *mrn,
+				     const struct mmu_notifier_range *range)
 {
-	struct amdgpu_bo *bo;
+	struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
+	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
 	long r;
 
-	list_for_each_entry(bo, &node->bos, mn_list) {
-
-		if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start, end))
-			continue;
-
-		r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv,
-			true, false, MAX_SCHEDULE_TIMEOUT);
-		if (r <= 0)
-			DRM_ERROR("(%ld) failed to wait for user bo\n", r);
-	}
+	/* FIXME: Is this necessary? */
+	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
+					  range->end))
+		return true;
+
+	if (!mmu_notifier_range_blockable(range))
+		return false;
+
+	mutex_lock(&adev->notifier_lock);
+	r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
+				      MAX_SCHEDULE_TIMEOUT);
+	mutex_unlock(&adev->notifier_lock);
+	if (r <= 0)
+		DRM_ERROR("(%ld) failed to wait for user bo\n", r);
+	return true;
 }
 
+static const struct mmu_range_notifier_ops amdgpu_mn_gfx_ops = {
+	.invalidate = amdgpu_mn_invalidate_gfx,
+};
+
 /**
- * amdgpu_mn_sync_pagetables_gfx - callback to notify about mm change
+ * amdgpu_mn_invalidate_hsa - callback to notify about mm change
  *
- * @mirror: the hmm_mirror (mm) is about to update
- * @update: the update start, end address
+ * @mrn: the range (mm) is about to update
+ * @range: details on the invalidation
  *
- * Block for operations on BOs to finish and mark pages as accessed and
- * potentially dirty.
+ * We temporarily evict the BO attached to this range. This necessitates
+ * evicting all user-mode queues of the process.
  */
-static int
-amdgpu_mn_sync_pagetables_gfx(struct hmm_mirror *mirror,
-			      const struct mmu_notifier_range *update)
+static bool amdgpu_mn_invalidate_hsa(struct mmu_range_notifier *mrn,
+				     const struct mmu_notifier_range *range)
 {
-	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
-	unsigned long start = update->start;
-	unsigned long end = update->end;
-	bool blockable = mmu_notifier_range_blockable(update);
-	struct interval_tree_node *it;
-
-	/* notification is exclusive, but interval is inclusive */
-	end -= 1;
-
-	/* TODO we should be able to split locking for interval tree and
-	 * amdgpu_mn_invalidate_node
-	 */
-	if (amdgpu_mn_read_lock(amn, blockable))
-		return -EAGAIN;
-
-	it = interval_tree_iter_first(&amn->objects, start, end);
-	while (it) {
-		struct amdgpu_mn_node *node;
-
-		if (!blockable) {
-			amdgpu_mn_read_unlock(amn);
-			return -EAGAIN;
-		}
+	struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
+	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
 
-		node = container_of(it, struct amdgpu_mn_node, it);
-		it = interval_tree_iter_next(it, start, end);
+	/* FIXME: Is this necessary? */
+	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
+					  range->end))
+		return true;
 
-		amdgpu_mn_invalidate_node(node, start, end);
-	}
+	if (!mmu_notifier_range_blockable(range))
+		return false;
 
-	amdgpu_mn_read_unlock(amn);
+	mutex_lock(&adev->notifier_lock);
+	amdgpu_amdkfd_evict_userptr(bo->kfd_bo, bo->notifier.mm);
+	mutex_unlock(&adev->notifier_lock);
 
-	return 0;
+	return true;
 }
 
-/**
- * amdgpu_mn_sync_pagetables_hsa - callback to notify about mm change
- *
- * @mirror: the hmm_mirror (mm) is about to update
- * @update: the update start, end address
- *
- * We temporarily evict all BOs between start and end. This
- * necessitates evicting all user-mode queues of the process. The BOs
- * are restorted in amdgpu_mn_invalidate_range_end_hsa.
- */
-static int
-amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror *mirror,
-			      const struct mmu_notifier_range *update)
+static const struct mmu_range_notifier_ops amdgpu_mn_hsa_ops = {
+	.invalidate = amdgpu_mn_invalidate_hsa,
+};
+
+static int amdgpu_mn_sync_pagetables(struct hmm_mirror *mirror,
+				     const struct mmu_notifier_range *update)
 {
 	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
-	unsigned long start = update->start;
-	unsigned long end = update->end;
-	bool blockable = mmu_notifier_range_blockable(update);
-	struct interval_tree_node *it;
 
-	/* notification is exclusive, but interval is inclusive */
-	end -= 1;
-
-	if (amdgpu_mn_read_lock(amn, blockable))
-		return -EAGAIN;
-
-	it = interval_tree_iter_first(&amn->objects, start, end);
-	while (it) {
-		struct amdgpu_mn_node *node;
-		struct amdgpu_bo *bo;
-
-		if (!blockable) {
-			amdgpu_mn_read_unlock(amn);
-			return -EAGAIN;
-		}
-
-		node = container_of(it, struct amdgpu_mn_node, it);
-		it = interval_tree_iter_next(it, start, end);
-
-		list_for_each_entry(bo, &node->bos, mn_list) {
-			struct kgd_mem *mem = bo->kfd_bo;
-
-			if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
-							 start, end))
-				amdgpu_amdkfd_evict_userptr(mem, amn->mm);
-		}
-	}
-
-	amdgpu_mn_read_unlock(amn);
+	if (!mmu_notifier_range_blockable(update))
+		return false;
 
+	down_read(&amn->lock);
+	up_read(&amn->lock);
 	return 0;
 }
 
@@ -295,12 +164,10 @@  amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror *mirror,
 
 static struct hmm_mirror_ops amdgpu_hmm_mirror_ops[] = {
 	[AMDGPU_MN_TYPE_GFX] = {
-		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_gfx,
-		.release = amdgpu_hmm_mirror_release
+		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables,
 	},
 	[AMDGPU_MN_TYPE_HSA] = {
-		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_hsa,
-		.release = amdgpu_hmm_mirror_release
+		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables,
 	},
 };
 
@@ -327,7 +194,8 @@  struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
 	}
 
 	hash_for_each_possible(adev->mn_hash, amn, node, key)
-		if (AMDGPU_MN_KEY(amn->mm, amn->type) == key)
+		if (AMDGPU_MN_KEY(amn->mirror.hmm->mmu_notifier.mm,
+				  amn->type) == key)
 			goto release_locks;
 
 	amn = kzalloc(sizeof(*amn), GFP_KERNEL);
@@ -337,10 +205,8 @@  struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
 	}
 
 	amn->adev = adev;
-	amn->mm = mm;
 	init_rwsem(&amn->lock);
 	amn->type = type;
-	amn->objects = RB_ROOT_CACHED;
 
 	amn->mirror.ops = &amdgpu_hmm_mirror_ops[type];
 	r = hmm_mirror_register(&amn->mirror, mm);
@@ -369,100 +235,33 @@  struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
  * @bo: amdgpu buffer object
  * @addr: userptr addr we should monitor
  *
- * Registers an HMM mirror for the given BO at the specified address.
+ * Registers a mmu_notifier for the given BO at the specified address.
  * Returns 0 on success, -ERRNO if anything goes wrong.
  */
 int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
 {
-	unsigned long end = addr + amdgpu_bo_size(bo) - 1;
-	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
-	enum amdgpu_mn_type type =
-		bo->kfd_bo ? AMDGPU_MN_TYPE_HSA : AMDGPU_MN_TYPE_GFX;
-	struct amdgpu_mn *amn;
-	struct amdgpu_mn_node *node = NULL, *new_node;
-	struct list_head bos;
-	struct interval_tree_node *it;
-
-	amn = amdgpu_mn_get(adev, type);
-	if (IS_ERR(amn))
-		return PTR_ERR(amn);
-
-	new_node = kmalloc(sizeof(*new_node), GFP_KERNEL);
-	if (!new_node)
-		return -ENOMEM;
-
-	INIT_LIST_HEAD(&bos);
-
-	down_write(&amn->lock);
-
-	while ((it = interval_tree_iter_first(&amn->objects, addr, end))) {
-		kfree(node);
-		node = container_of(it, struct amdgpu_mn_node, it);
-		interval_tree_remove(&node->it, &amn->objects);
-		addr = min(it->start, addr);
-		end = max(it->last, end);
-		list_splice(&node->bos, &bos);
-	}
-
-	if (!node)
-		node = new_node;
+	if (bo->kfd_bo)
+		bo->notifier.ops = &amdgpu_mn_hsa_ops;
 	else
-		kfree(new_node);
-
-	bo->mn = amn;
-
-	node->it.start = addr;
-	node->it.last = end;
-	INIT_LIST_HEAD(&node->bos);
-	list_splice(&bos, &node->bos);
-	list_add(&bo->mn_list, &node->bos);
+		bo->notifier.ops = &amdgpu_mn_gfx_ops;
 
-	interval_tree_insert(&node->it, &amn->objects);
-
-	up_write(&amn->lock);
-
-	return 0;
+	return mmu_range_notifier_insert(&bo->notifier, addr,
+					 amdgpu_bo_size(bo), current->mm);
 }
 
 /**
- * amdgpu_mn_unregister - unregister a BO for HMM mirror updates
+ * amdgpu_mn_unregister - unregister a BO for notifier updates
  *
  * @bo: amdgpu buffer object
  *
- * Remove any registration of HMM mirror updates from the buffer object.
+ * Remove any registration of mmu notifier updates from the buffer object.
  */
 void amdgpu_mn_unregister(struct amdgpu_bo *bo)
 {
-	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
-	struct amdgpu_mn *amn;
-	struct list_head *head;
-
-	mutex_lock(&adev->mn_lock);
-
-	amn = bo->mn;
-	if (amn == NULL) {
-		mutex_unlock(&adev->mn_lock);
+	if (!bo->notifier.mm)
 		return;
-	}
-
-	down_write(&amn->lock);
-
-	/* save the next list entry for later */
-	head = bo->mn_list.next;
-
-	bo->mn = NULL;
-	list_del_init(&bo->mn_list);
-
-	if (list_empty(head)) {
-		struct amdgpu_mn_node *node;
-
-		node = container_of(head, struct amdgpu_mn_node, bos);
-		interval_tree_remove(&node->it, &amn->objects);
-		kfree(node);
-	}
-
-	up_write(&amn->lock);
-	mutex_unlock(&adev->mn_lock);
+	mmu_range_notifier_remove(&bo->notifier);
+	bo->notifier.mm = NULL;
 }
 
 /* flags used by HMM internal, not related to CPU/GPU PTE flags */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
index b8ed68943625c2..d73ab2947b22b2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
@@ -39,12 +39,10 @@  enum amdgpu_mn_type {
  * struct amdgpu_mn
  *
  * @adev: amdgpu device pointer
- * @mm: process address space
  * @type: type of MMU notifier
  * @work: destruction work item
  * @node: hash table node to find structure by adev and mn
  * @lock: rw semaphore protecting the notifier nodes
- * @objects: interval tree containing amdgpu_mn_nodes
  * @mirror: HMM mirror function support
  *
  * Data for each amdgpu device and process address space.
@@ -52,7 +50,6 @@  enum amdgpu_mn_type {
 struct amdgpu_mn {
 	/* constant after initialisation */
 	struct amdgpu_device	*adev;
-	struct mm_struct	*mm;
 	enum amdgpu_mn_type	type;
 
 	/* only used on destruction */
@@ -63,7 +60,6 @@  struct amdgpu_mn {
 
 	/* objects protected by lock */
 	struct rw_semaphore	lock;
-	struct rb_root_cached	objects;
 
 #ifdef CONFIG_HMM_MIRROR
 	/* HMM mirror */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
index 658f4c9779b704..4b44ab850f94c2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
@@ -30,6 +30,9 @@ 
 
 #include <drm/amdgpu_drm.h>
 #include "amdgpu.h"
+#ifdef CONFIG_MMU_NOTIFIER
+#include <linux/mmu_notifier.h>
+#endif
 
 #define AMDGPU_BO_INVALID_OFFSET	LONG_MAX
 #define AMDGPU_BO_MAX_PLACEMENTS	3
@@ -100,10 +103,12 @@  struct amdgpu_bo {
 	struct ttm_bo_kmap_obj		dma_buf_vmap;
 	struct amdgpu_mn		*mn;
 
-	union {
-		struct list_head	mn_list;
-		struct list_head	shadow_list;
-	};
+
+#ifdef CONFIG_MMU_NOTIFIER
+	struct mmu_range_notifier	notifier;
+#endif
+
+	struct list_head		shadow_list;
 
 	struct kgd_mem                  *kfd_bo;
 };